Friday 7 October 2011 17.55 EDT
First published on Friday 7 October 2011 17.55 EDT

"These Muslas," says Joseph Bhatti, father of Alice, "will make you clean their shit and then complain that you stink." This is pretty close to the mark. Pakistan won't forget the low-caste origins of most of its Christians, or "Choohras" – the derogatory term refers to their status as an "untouchable" sweeper and maid class. In recent decades, with the rise of increasingly intolerant forms of Islam, the Choohra plight has worsened. Christians are victims of obscene blasphemy laws and frequent sectarian violence.

How refreshing, therefore, that Mohammed Hanif, Booker-longlisted author of A Case of Exploding Mangoes and perhaps Pakistan's brightest English-language voice, has chosen to view his country through the eyes of a (lapsed) Christian – the eponymous Alice Bhatti, a hard-nosed, warm-hearted nurse, too beautiful for her own good, also nifty with a razor blade.

Her lover and foil is the "Musla" Teddy Butt, a thigh-waxing, body-building, Mauser-packing lowlife. Teddy works unofficially for the Gentlemen's Squad, a police unit somewhat darker than the Keystone Cops staffed by partially reformed rapists, torturers and sharpshooters. A need for protection propels Alice into Teddy's arms, and his courtship afterwards has a certain flair. They are married, improbably, on a nuclear submarine.

Their love story ends badly, though Hanif's narration concludes with absurd religious optimism, a parody of beatification that includes a couple of delicious swipes at Mother Teresa. The lovers' lives are framed by institutions, from borstal to hospital via police station and nursing school. The Sacred, where Alice works and the characters meet, is a rat-infested place "where half a pint of O-positive costs 200 rupees". In the compound outside, beggars, miracle-seekers and aspiring patients sleep among the roots of the Old Doctor, "a 200-year-old peepal tree that was believed to provide medical care before they built a hospital".

At one point Hanif alludes to Saadat Hasan Manto's classic story "Toba Tek Singh", which epitomises the crisis of the India-Pakistan partition in a mental asylum. Our Lady of Alice Bhatti is certainly not allegorical – it has too much unruly life of its own to fit smoothly into any neat political scheme – but it is somehow representative, broadly suggestive of the sad state of a nation.

The story is set in Karachi, where ethnic, religious and gang violence has killed at least 1,300 people this year. Hanif does Karachi better than Rushdie does Bombay; his city is startlingly detailed but not exoticised, more realist than romantic, yet faithful to Karachi's strangeness, teetering always on the edge of the surreal. It's a smog-thick zone, bristling with guns, and chaotically interconnected. When Teddy absent-mindedly shoots a Pashtun truck driver, the ensuing chain of bloody events immobilises the city for three days. Universal criminality, in which the straightforward criminals are perhaps the least guilty of all, underpins the metropolis like the stink of its sewers.

The novel is full of fine little touches that are never pushed too far, as when a man selling copies of the Daily Ummah ignores a murder-in-progress – ummah is the term denoting the global Islamic moral community. The social satire homes in on graffiti, TV banalities, advertisements, the pretensions of the thuggish rich and the accommodations of the struggling poor.

For too many writers the poor are grim decorations or zoological curiosities; Hanif, on the other hand, knows his way inside his characters, into their sexualities, fears, resentments and hopes. He transmits their complexities and their deadly simplicities. Their mouths, like his, constantly spill jokes, wittingly and unwittingly.

This very finely put-together novel sparkles and glitters but never shows off. It's a comedy possessing the quality Calvino called lightness, but it's deeper than it first appears. Here too, almost unannounced, there's a subtle interrogation of faith and faithlessness. Perhaps Hanif's Christian protagonist permits the articulation of thoughts that would otherwise seem too controversial. Alice thinks to herself that Muslims at prayer look ungainly, then adds: "Not that you can think about these things in public and hope to live."

Hanif's novel is relentlessly readable, compulsively so as it surges towards its apocalyptic conclusion. The chapters, all written with the immediacy of the present tense, dance around in time without for a moment losing their coherence. And sometimes the prose attains the heights of poetry: "The man with the x-rays is trying to shoo away a kite, which, confused by the sudden change in light, thinks it is dusk and swoops down in a last desperate attempt to take something home. The legless man is fighting the kite with the x-rays of his missing legs."

Our Lady of Alice Bhatti is a book like life, a comedy for those who think, a tragedy for those who feel. The tone is profoundly humane, and humanist. "How about real miracles," asks Alice, "like the drains shall remain unclogged? Or the hungry shall be fed?"